Glider construction



July 23, 1963 M. PEARLSTINE GLIDER cousmucmn 2 Sheets-Sheet 1 Filed June 6, 1960 INVENTOR. M01970 PA'AIPLS mu;

July 23, 1963 M. PEARLSTINE GLIDER CONSTRUCTION 2 Sheets-Sheet 2 Filed June 6, 1960 INV EN TOR. M01? 7011/ F571,?! S7//1/ United States Patent 3,098,678 GLIDER CONSTRUCTION Morton Pearlstine, Bala-Cynwyd, Pa., assignor to The Bunting Company, Inc., Philadelphia, Pa., a corporation of Pennsylvania Filed June 6, 1960, Ser. No. 34,252 Claims. (Cl. 297-344) This invention relates to sitting furniture, and more particularly relates to sitting furniture of the glider type as disclosed in my earlier filed co-pending application for United States Letters Patent, Serial No. 748,889, filed July 16, 1958, now Patent No. 2,959,210, the instant application being a continuation-in-part thereof and representing an improvement thereover in certain particulars. Gliders are characterized by their ability to oscillate with a generally forward and backward gliding motion under the control of an occupant of the glider seat, such motion giving rise to the generic name glider.

In the past, various types of socalled gliders have been devised which provide a motion more nearly like that of a swing than that of a true glider but which nevertheless are classed as gliders. Generally, these devices include a stand which rests on the floor and from which is freely suspended by pivoted vertical hangers a seat of some kind. As the seat is moved back and forth by the occupant it rises and falls much in the manner of a pendulum. Moreover, because of the hanger suspension system, an appreciable undesirable side-sway usually occurs unless the fore and back motion is restricted. The combined pendulum motion and side-sway is generally unpleasant and is sometimes unsettling to the stomach. Also annoying is the tendency of the seat to knock against the stand when the glider is being operated which causes the seat to twist and shudder. lMy invention differs from these so-called gliders in that it is not subject to the shortcomings hereinbefore described, but is in fact a true glider and not a modified swing.

The glide mechanism according to the invention, as set forth in complete detail in my aforesaid co-pending application for United States Letters Patent, utilizes a pair of horizontally extending parallel tracks spaced vertically one above the other and separated by a pair of intervening ball bearings. The lower track of the pair is formed with a pair of spaced apart dirnpled depressions, one of the ball bearings being normally disposed in the bottom of each depression when the glider is in its centered atrest position. As the glider is shifted fore and aft, it is desired that the ball bearings roll forward and backward in the depressions while maintaining a constant interball spacing.

It has been found that after a period of extended use there may occur a noticeable change in the interball spac ing, so that, while one ball may be disposed in the bottom of its associated depression, the other ball may be found to have wandered and be somewhat displaced from the bottom of its depression. This condition is, of course, undesirable since it tends to decrease the at-rest stability of the glider. The present invention is directed toward elimination of this condition by providing relatively simple, but highly effective, means for insuring the constancy of the interball spacing. Accordingly, it is a principal object of my invention to provide a novel glider whose seat motion is characterized by being substantially rectilinear in the fore and back direction.

Another object of my invention is to provide a novel glider which is free of side-sway during use.

Still another object of my invention is to provide a novel glider which has no tendency to impart a twisting motion to the seat when the latter is in motion.

Yet another object of my invention is to provide a novel glider which has a stable rest position from which the seat does not tend to wander unless urged by an occupant.

A still further object of my invention is to provide a novel glider which utilizes a pair of ball bearings spaced apart longitudinally along the length of and disposed between a pair of vertically separated parallel extending tracks, and the provision of novel means for maintaining constant the spacing between the ball bearings.

The foregoing and other objects will become clear from a careful reading of the following specification in conjunction with an examination of the several drawings, where- FIGURE 1 is a perspective view of a multiple seat glider constructed according to and embodying the principles of the invention;

FIGURE 2 is a side elevation of the glider of FIGURE 1 illustrating the seat in rearward displaced position;

FIGURE 3 is an enlarged exploded perspective view of the improved gliding mechanism according to the invention;

FIGURE 4 is an enlarged fragmented side sectional view of the improved gliding mechanism illustrating the ball-bearing support for the seat frame;

FIGURE 5 is a cross-sectional view of the improved glide mechanism taken along the lines 5-5 of FIGURE 1; and,

FIGURE 6 is a cross-sectional view of the improved glide mechanism taken along the lines 6-6 of FIG- URE 1.

In the several figures, like elements are identified by the same reference numerals.

Turning now to a consideration of FIGURES 1 and 2 for a general understanding of the glider structure and manner of operation, it will be seen that the glider consists essentially of three major types of functional unit. The first functional unit includes a back-rest assembly 10 and a pair of side frame and arm-rest assemblies '11 secured to a seat assembly 12. The second functional unit consists of a pair of double track assemblies 13, which assemblies include a pair of floor engaging lower track sections 14 and a pair of upper track sections 15, to which latter sections the side frames 11 of the first unit are secured. A pair of ball bearings 16 between the upper and lower track sections of each double track assembly 13 provide a low friction translation bearing which permits relative fore and aft motion of the upper track sections 15 relative to the lower track sections '14. Since the side frames 11 of the first unit are rigidly secured tothe upper track sections 15 of the second unit, the first unit will, of course, travel with the upper tracks 15 as they move fore and aft. Each double track assembly 13 also includes a pair of lateral retainer brackets 17 secured to the lower track section 14 and extending non-engagingly upward on both sides of each upper track section 15 to prevent the latter from sidewise shifting. The third functional unit consists of a pair of linkages 18 rigidly secured at their upper end to the seat assembly 12 and side frame assemblies 11 of the first unit by an eye bolt 19, and pivotally secured at their lower end to the lower track section 14 of the second functional units by a yoke 20. The eye bolt 19 and yoke 20 are intercoupled by an extensible spring 21.

In operation, the first functional unit and the upper track sections 15 ride back and forth on the ball bearings 16 which roll in the bottom track sections 14 along a straight-line path, thus accomplishing the objects of eliminating the undesirable pendulum swing motion, sidesway, and twisting motion previously described. The linkages 18, together with a particular structural configuration of the track sections 14 and 15 to be subsequently described, operate to provide a stable rest position from which the seat does not tend to wander unless urged by an occupant. As the seat moves either backward or forward from its at-rest position illustrated in FIGURE 1, the spring 21 of the linkage 18 is stretched and, therefore, exerts a restoring force which tends to pull the seat back to the centered at-rest position. FIGURE 2 illustrates a backward displaced condition of the seat, and it is readily seen that the yoke 20 has tilted backwards in response to the pull of the stretched spring 21.

For a clear understanding, of the constructional details of the invention turn now to a consideration or" FIG- URES 3, 4, 5 and 6. The cross-sectional views of FIG- URES 5 and 6 show that the upper and lower track sec tions 15 and 14 illustrated in the other figures preferably comprise a pair of tubular members depressed inward to form a V-shaped groove extending substantially the entire length of each member, the grooved faces presenting vertically toward each other and held in spaced relation by the ball bearings 16. As best seen in 'FIGURE 4, the rivets 28 secure the lateral retainer brackets 17 to the lower track section 14, the rivets 27 secure the foot pads 26 also to the lower track section, and the bolts l9 secure the lower rail of the side frames 11 to the upper track section 15. As best seen in FIGURES 3 and 5, the yoke 20 of the linkage 18 is pivotally horizontally pinned to the lower track section 14 by the bolt assembly 30. The bolt assembly 30 includes the bushings 3'5, bolt 37 and nut 3-9. Assembly of the yoke 20 to the track 14 is carried out by projecting the bushings 35 outward through the bushing holes 36 in the yoke 20, aligning the bolt-receiving holes 38 in the track 14 with the bores through the bushings 3'5, projecting the bolt 37 through the bushings and the track and securing the bolt end with the nut 39. The clearest view of the assembled yoke 20 and track 14 is illustrated in the showing of FIGURE 5, wherein it will be observed that the bushings 35, which are made of a low friction material, prevent metal-to-metal contact between the yoke and the track so that the yoke is freely pivotable on the bushings.

The sectional view of FIGURE 4 additionally shows that the track section 14 is dimpled downward, as at 31, to provide a very shallow but definite valley. These dimples are so located that the ball bearings 16 lie therein when the seat is in its centered at-rest position as illustrated in FIGURE 1. By virtue of this dimpled construc tion and the spring-loaded linkages 18, the seat tends to remain in its centered position when the occupant does not actively urge it backward or forward. It should be noted that the shallowness of the valley and smoothness of curvature are such as to preclude any awareness by the seat occupant of departure from straight line motion while at the same time being sufficient to efiect the at-rest centering of the seat. In this figure, the ball bearings 16 are illustrated forward of the valley bottom and the yoke 20 is seen to be pivoted forward, whereas in FIGURE 2 the ball bearings are shown rearward of the valley bottom and the yoke 20 is pivoted backward, corresponding, of course, respectively to forward and rearward displacement of the seat.

The aforedescribed portions of the apparatus are substantially the same structurally and functionally as their corresponding parts shown and described in my aforesaid co-pending application for United States Letters Patent. As pointed out hereinbefore, it has been found that after a period of extended use there may occur a noticeable change in the spacing between the ball bearings 16, so that, while one ball hearing may be disposed in the bottom of its associated dimpled depression 31, the other ball hearing may be found to have assumed a position somewhat displaced from the bottom of its associated depression, thus tending to decrease the at-rest stability of the glider.

This creep, or wandering, of one ball bearing relative to the other is believed to result from the difference in path length traversed by the ball bearing points of con tact points with the upper tracktraversing a shorter path than the contact points with the lower track because the upper track is straight while the lower track is curved in the depressed regions 31. The ball bearings would, therefore, appear to roll on one track, and at certain points to slide on the other track for very small but finite distances, thereby resulting in a slight displacement. The small displacements may aggregate over a period of time and result in the aforenoted relative shift between the ball bearings.

The elimination of this creep efiect is achieved in the present invention by providing means for substantially equalizing the path length traversed by the ball bearing points of contact with both tracks, and by additionally incorporating a ball bearing harness device which insures control of any long term residual creep effect due to incomplete symmetry of the tracks arising as a consequence of manufacturing tolerances. As will be seen, the harness device may also act as a ball bearing captive and motion limiting apparatus.

FIGURES 3 and 4 illustrate the path length equalizing means, wherein it is observed that the upper track 15 has been provided with a pair of dimpled depressions 31 spaced apart lengthwise of the track by the same amount as the lower track depressions 31 are spaced from one another, the depressions 31 being symmetrical to the depressions 31. Observation of FIGURE 4 also shows that the upper and lower tracks 15 and 114 respectively are identical except for the end depressions in the lower track where the pads 26 are secured by the rivets 27, and thus both tracks may be formed with the same equipment to thereby insure very close symmetry in the regions of importance, namely the depressions 31 and 3-1.

The harness device is seen in various aspects in all of the figures, a perspective view being shown in FIGURE 3 and sectional views being illustrated in FIGURES 4, 5 and 6. Referring first to FIGURE 3, the harness is observed to include a pair of generally C-shaped yoke members 40, spaced apart a distance equal to the spacing between the bottoms of the spaced depressions 31 in the lower track 14 or 3.1 in the upper track 15. Each of the yoke members 40 includes a central portion 41 and a pair of incurved arms 42 extending downward from opposite sides of the central portion, the central portion being apertured, as at 43, so that the ball bearings 16 may project upward partially therethnough for rolling contact with the upper track 15. The yoke members 40 are coupled together in fixed spaced apart relation by means of the tie rod 44 whose opposite ends 45 are projected through holes in the central portions 41 and turned back upon themselves for securement.

As best seen in FIGURES 4, 5 and 6, the diameter of the ball bearings 16 is somewhat larger than the diameter of the apertures 43 in the yoke members 40 so that the ball bearings cannot pass upward completely therethrough. Moreover, the arms 42 of the yoke members 40 are curved inward under the lower track '14, so that while each yoke 40 may shift longitudinally along the track it may not be shifted in a vertical direction. The ball bearings 16 are thus held captive between the track 14 and the central portion 41 of the C-shaped yoke members 40, while at the same time being free to roll in the lower track.

Finally, the harness device also provides a motion limiting eifect which prevents the ball bearings 16 from riding longitudinally out of the depressions 31 in the lower track to thereby preclude either ball hearing from running beyond the end of the track. The manner of achieving this result is most clearly seen in the showing of FIGURE 4, wherein it will be observed that continued right-directed travel of the ball bearings causes them to rise vertically along the forward slope of the depressions 31. The yoke members 40 are necessarily carried upward with the ball bearings 16 upon which they are seated, and, of course, it is evident that the yoke arms 42 rise therewith until they contact the underside of the track 14, being thereupon prevented from further motion V and in turn restraining additional shifting of the ball bearings longitudinally of the lower track 14. The same mechanism obviously is operative in the reverse direction.

In the various figures, the parts illustrated may be made of any suitable materials. For example, the backrest frame 32, seat frame 33, side frame 11, and side frame tie-rods 34 may be made of wood or metal; the several parts of the linkages 18 and ball bearing harness devices are preferably made of metal, as are the parts of the upper and lower track assemblies; and the bushings 35 of the yoke bolt assembly 30- may be made of a suitable plastic material, as for example nylon.

It will be understood, of course, that the present in vention is susceptible to various changes and modifications which may be made'from time to time without departing from the real spirit or general principles thereof, and accordingly, it isintended to claim the same broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a glider, in combination, a rigid superstructure including a seat and back rest unit, a pair of laterally spaced parallel straight tracks secured to the bottom of said superstructure and extending fore and aft thereof, a pair of floor-supported elongated straight tracks respectively disposed beneath and in substantial vertical registry with said superstructure straight tracks, and plural revoluble bearing means interposed between each floor-supported track and its associated superstructure track for supporting said superstructure upon said floor supported tracks for gliding movement therealong in opposite directions from an at-rest position, said revoluble bearing means being free to move longitudinally of both tracks between which it is disposed when said tracks move longitudinally relative to each other, each of said floor-supported straight tracks being formed with a pair of shallow depressions therein spaced apart longitudinally along the track length within which first and second portions of said plural revolu ble bearing means are respectively disposed when the glider is in its normal at-rest position, each of said superstructure straight traclcs being formed with a pair of shallow depressions therein spaced apart longitudinally along the track length and positioned immediately above and in facing relation to the shallow depressions in the belowlying floor-supported track so that said revoluble bearing means are also disposed respectively therewithin when the glider is in its normal at-rest position, and harness means intercoupling the spaced apart first and second portions of the plural revoluble bearing means disposed between each floor-supported track and its associated superstructure track, said harness means being carried by and shifting with said bearing means when the latter move longitudinally along said tracks and including means to maintain substantially constant the spacing between the intercoupled portions of the revoluble bearing means.

2. The combination according to claim 1 wherein said first and second portions of said plural revoluble bearing means each comprise a ball bearing, and wherein said harness means intercoupling the spaced-apart ball bearings comp-rises a pair of top-aperturedyokes respectively seated upon said ball bearings so that the latter project partially upward through the associated yoke aperture for contact with the superstructure track, said yokes being coupled to one another by :a rigid tie member extending therebetween.

3. The combination comprising a superstructure including a seat for an occupant, a double track assembly including a first straight track adapted to rest on a supporting surface and :a second straight track adapted for longitudinal movement relative to said first straight track, said second straight track being parallel to and spaced vertically above said first straight track and being non-engagingly underlyingly supported thereby through an interposing pair of ball bearings spaced apart lengthwise of said tracks, said ball bearings being longitudinally shiftable relative to both of said tracks and determining the vertical spacing therebetween while maintaining said tracks in said vertically spaced parallel relation by restricting relative lateral movement therebetween, said superstructure being secured to said second track for movement therewith in fore and aft directions from an at-rest position relative to said first track, and a resiliently distendable linkage, one part of said linkage being secured to said superstructure and second track assembly and another part of said linkage being secured to said first track, whereby said superstructure and said second track assume the at-rest position relative to said first track when said linkage is in its minimum distended condition and are biased toward the at-rest position when said linkage is distended beyond said minimum distended condition as a result of departure of said superstructure and second track in either direction from the at-rest position, said spaced apart ball bearings being coupled together at a fixed separation by harness means extending therebetween, said harness means being partly disposed between said first and second tracks and partly disposed in embracing rela tion to said first track.

4. In a glider, in combination, a rigid superstructure including a seat and back rest unit, a pair of laterally spaced parallel tracks secured to the bottom said said superstructure and extending fore and aft thereof, a pair of floor-supported elongated tracks respectively disposed beneath and in substantial vertical registry with said superstructure tracks, a pair of ball bearings spaced apart longitudinally of and interposed between each floor-supported track and its associated superstructure track for supporting said superstructure upon said floor-supported tracks for gliding movement therealong in opposite directions from an at-rest position, said ball bearings being free to move longitudinally of both tracks between which they are disposed when said tracks move longitudinally relative to each other, each of said floor-supported tracks being formed with a pair of longitudinally spaced apart depressions therein with said pair of ball bearings disposed respectively therein when the glider is in its normal at rest position, each of said superstructure tracks being formed with a pair of longitudinally spaced apart depressions therein positioned immediately above and in facing relation to the pair of depressions in the below-lying floor-supported track so that said pair of ball bearings are also disposed therewithin when the glider is in its normal at-rest position, harness means carried by and intercoupling the pair of ball bearings disposed between each floor-supported track and its associated superstructure track, said harness means shifting with said ball bearings when the latter move longitudinally along said tracks and including a pair of spaced apart top-ape-rt-ured yokes respectively seated upon said pair of ball bearings so that the latter project partially upward through the associated yoke aperture for contact with the superstructure track with the pair of yokes coupled to one another by a rigid tie member extending therebetween, each of said yokes including a pair of arms extending downward on opposite sides of said floor-supported track, said yoke arms turning inward toward one another and each underlying a portion of said floor-supported track to prevent more than a predetermined amount of vertical movement of each yoke relative to its associated track.

5. The combination comprising a superstructure including a seat for an occupant, a double track assembly including a first track adapted to rest on a supporting surface and a second track adapted for longitudinal movement relative to said first track, said second track being parallel to and spaced vertically above said first track and being nonengagingly underlyingly supported thereby through an interposing pair of ball bearings spaced apart lengthwise of said tracks, said ball bearings being longitudinal-1y shiftable relative to both of said tracks and determining the vertical spacing therebetween while maintaining said tracks in said vertically spaced parallel relation by re- 7 stricting relative lateral movement therebetween, said superstructure being secured to said second traek for movement therewith in fore and aft directions from an at-rest position relative to said first track, and a resiliently distendable linkage, one part of said linkage being secured to said superstructure and second track assembly and another part of said linkage being secured to said first track, whereby said'superstructure and said second track assume the at-rest position relative to said first track when said linkage is in its minimum distended condition and are biased toward the at-rest position when said linkage is distended beyond said minimum distended condition as a result of departure of said superstructure and second track in either directionfrom the at-rest position, said spaced apart ball bearings being coupled together at a fixed separation by harness means extending therebetween, said harness means being partly disposed between said firs-t and second tracks and partly disposed in embracing relation to said first track, said harness means comprising a spaced apart pair of generally C-shaped yokes intercoupled by a rigid tie member extending therebetween, the arms of each C-shaped yoke extending downward and inward about said first track, and the yoke portion between the said arms being apes-tilted and seated upon one of said ball bearings so that the latter projects upward partially through the yoke aperture into contact with the second track, each ball bearing being thereby held captive between the apertured portion of a yoke and the underlying first track.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A GLIDER, IN COMBINATION, A RIGID SUPERSTRUCTURE INCLUDING A SEAT AND A BACK REST UNIT, A PAIR OF LATERALLY SPACED PARALLEL STRAIGHT TRACKS SECURED TO THE BOTTOM OF SAID SUPERSTRUCTURE AND EXTENDING FORE AND AFT THEREOF, A PAIR OF FLOOR-SUPPORTED ELONGATED STRAIGHT TRACKS RESPECTIVELY DISPOSED BENEATH AND IN SUBSTANTIAL VERTICAL REGISTRY WITH SAID SUPERSTRUCTURE STRAIGHT TRACKS, AND PLURAL REVOLUBLE BEARING MEANS INTERPOSED BETWEEN EACH FLOOR-SUPPORTED TRACK AND ITS ASSOCIATED SUPERSTRUCTURE TRACK FOR SUPORTING SAID SUPERSTRUCTURE UPON SAID FLOOR SUPPORTED TRACKS FOR GUIDING MOVEMENT THEREALONG IN OPPOSITE DIRECTIONS FROM AN AT-REST POSITION, SAID REVOLUBLE BEARING MEANS BEING FREE TO MOVE LONGITUDINALLY OF BOTH TRACKS BETWEEN WHICH IT IS DISPOSED WHEN SAID TRACKS MOVE LONGITUDINALLY RELATIVE TO EACH OTHER, EACH OF SAID FLOOR-SUPPORTED STRAIGHT TRACKS BEING FORMED WITH A PAIR OF SHALLOW DEPRESSIONS THEREIN SPACED APART LONGITUDINALLY ALONG THE TRACK LENGTH WITHIN WHICH FIRST AND SECOND PORTIONS OF SAID PLURAL REVOLUBLE BEARING MEANS ARE RESPECTIVELY DISPOSED WHEN THE GLIDER IS IN ITS NORMAL AT-REST POSITION, EACH OF SAID SUPERSTRUCTURE STRAIGHT TRACKS BEING FORMED WITH A PAIR OF SHALLOW DEPRESSIONS THEREIN SPACED APART LONGITUDINALLY ALONG THE TRACK LENGTH AND POSITIONED IMMEDIATELY ABOVE AND IN FACING RELATION TO THE SHALLOW DEPRESSIONS IN THE BELOWLYING FLOOR-SUPPORTED TRACK SO TAHT SAID REVOLUBLE BEARING MEANS ARE ALSO DISPOSED RESPECTIVELY THEREWITHIN WHEN THE GLIDER IS IN ITS NORMAL AT-REST POSITION, AND HARNESS MEANS INTERCOUPLING THE SPACED APART FIRST AND SECOND PORTIONS OF THE PLURAL REVOLUBLE BEARING MEANS DISPOSED BETWEEN EACH FLOOR-SUPPORTED TRACK AND ITS ASSOCIATED SUPERSTRUCTURE TRACK, SAID HARNESS MEANS BEING CARRIED BY AND SHIFTING WITH SAID BEARING MEANS WHEN THE LATTER MOVE LONGITUDINALLY ALONG SAID TRACK AND INCLUDING MEANS TO MAINTAIN SUBSTANTIALLY CONSTANT THE SPACING BETWEEN THE INTERCOUPLED PORTIONS OF THE REVOLUBLE BEARINGS MEANS. 